We did reform welfare ten years and it haven't slowed down illegal immigration- most people on welfare are women with children, not the type most prefer when it is time to build houses, especially when they can have able bodied men from Mexico. Many of the men who grew up in welfare culture have criminal records that make them unemployable.
Most of my neighbors use Mexican yard crews. I'm not crazy about it but I'd be more nervous if they were using black inner-city yard crews. And so would my neighbors, they'd be mowing their own lawns.
Of course when you have a generation or two of welfare whites, they'll be just as bad.
It wouldn't be easy to salvage a criminal welfare class but it can be done - Britain's Victorian reforms salvaged slums as bad as the U.S. has ever had. And now they're p---ing it away with their own welfare state and illegitimacy, and their own disgruntled immigrants of color.